1. Field Of The Invention
The present invention relates to a tool for controlling fluid flow at remote locations and more particularly to such a tool which has particular utility in wells quickly and easily to permit the discharge of hydrostatic pressure from well tubing or conduit within the well prior to and during removal of portions of the well conduit from the well so as to facilitate repositioning of the conduit and associated equipment within the well as well as to avoid the necessity for discharging the well fluids creating the hydrostatic pressure at the earth's surface which constitute both ecological and fire hazards and otherwise interfere with well operation. It will be recognized that, while the tool of the present invention was developed for and has particular utility for usage in wells of a variety of types, the tool also has utility of marked significance in many other areas of application where it is necessary to control the flow of fluids through and periodically divert the passage of fluids from a conduit at a remote location.
2. Description Of The Prior Art
It is necessary in well operation and particularly oil well operation to remove the fluid conductive well conduit from the well at periodic intervals during normal use of the well for repositioning of a submersible pump located at depth in the well, for servicing of the tubing and well casing, for servicing or replacement of the pump, for treatment of the formation laterally of the well casing and the like. Of course, normal operation of the well fills the conduit above the pump with fluid extending to the earth's surface. If the conduit is to be removed for any one of the various reasons, the conduit must be raised and disassembled section by section at the earth's surface. Unless preventive measures are taken, the fluid within those sections is discharged over the earth's surface at the well site as this process is performed. Such discharge of fluids at the surface is a serious impediment to operation of the well particularly where the fluid is oil which constitutes both an ecological and a fire hazard and interferes with continued operation of the well unless cleaned up after the process is completed.
Certain prior art devices have been developed which permit, with less than satisfactory degrees of success, discharge of this hydrostatic pressure from the well conduit during removal from the well thereby allowing such fluids to be discharged into the well from the conduit rather than being dumped at the earth's surface. However, such devices are legion in the relative complexity and delicateness of their structures. Such prior art devices commonly require that the conduit be secured on the interior of the well casing in order for them to operate. Similarly, these prior art devices typically require the replacement of seals each time the device is used thereby requiring the entire conduit string to be withdrawn from the well after such use even where this is not otherwise necessary. Furthermore, such devices have been found to be inoperable when subjected to high temperatures such as are experienced in steam injection wells. Consequently, such prior art devices have not been widely used in the industry. Furthermore, conventional manual procedures requiring swabbing of the interior of each section of conduit as it is withdrawn from the well are extremely burdensome and expensive.
Therefore, it has long been known that it would be desirable to have a tool for controlling fluid flow at remote locations which permits the controlled discharge of hydrostatic pressure from well conduit, as well as conduit employed in other areas, whereby well fluids can be discharged into the well from the conduit, which does not interfere with the normal operation of the conduit, pump and associated well equipment and which can be used repeatedly for its designated purpose without requiring removal from the well for servicing even when subjected to high temperatures.